<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<form action="/login" method="post">
账号:<input type="text" name="username">
密码:<input type="text" name="password">
    <button type="submit">提交</button>
</form>

<a href="/logout">退出</a>

<span th:text="${errorMessage}"></span>
</body>
</html>